Search results for "Fuller"
showing 10 items of 203 documents
Hydrogen Bonding Donor–Acceptor Carbon Nanostructure
2012
The natural process of photosynthesis is paradigmatic in converting sunlight into energy. This complicated process requires a cascade of energy- and electron-transfer events in a highly organised matrix of electron–donor, electron–acceptor and antennae units and has prompted researchers to emulate it. In fact, energy- and electron-transfer processes play a pivotal role in molecular-scale optoelectronics. In this chapter we compile a number of remarkable examples of noncovalent aggregates formed by the combination of carbon-based electroactive species (fullerenes and carbon nanotubes) hydrogen bonded with a variety of moieties. We will show that: (a) the connection of complementary electroac…
Behaviour of Nanomaterials in the Environment: A Study of Interaction between Humic Acids and Fullerene C60
2010
Interaction between buckminsterfullerene and humic substances of different origin was investigated using fluorescence spectrometry as function of concentration of humic substances, pH and ionic strength. Binding constants of humic substances and buckminsterfullerene were calculated. It can be suggested that the complexation was driven by hydrophobic interaction depending on properties of the interacting compounds. Hydrophobic interaction model was indicated by linear Stern–Volmer plot, and high Kd values characterized interaction between buckminsterfullerene and humic acids. The results of this study support the development of understanding of fate of nanomaterials in environment as well as…
Eight‐Coordinate Endohedral Rhenium, Osmium and Iridium Atoms in Rare‐Earth Halide Cluster Complexes
2010
Endohedral (interstitial) atoms are essential for almost all of the rare-earth halide cluster complexes. Most of these contain octahedral clusters, some are isolated, but the majority exhibits condensation by common edges to structures of higher dimensionality. Higher coordination numbers of the endohedral atoms are rare. Four examples of extended cluster complexes with eight-coordinate endohedral atoms of sixth-period elements (Re, Os, Ir) are presented. In the quasi-isostructural, non-isotypic halides (ReGd 4 )Br 4 and {OsSc 4 }-Cl 4 , square antiprisms of gadolinium and scandium atoms, respectively, are connected by two common faces to chains, surrounded and loosely connected by halogeni…
Kelvin probe force microscopy studies of the charge effects upon adsorption of carbon nanotubes and C 60 fullerenes on hydrogen-terminated diamond
2018
Hydrogen-terminated diamond is known for its unusually high surface conductivity that is ascribed to its negative electron affinity. In the presence of acceptor molecules, electrons are expected to transfer from the surface to the acceptor, resulting in p-type surface conductivity. Here, we present Kelvin probe force microscopy (KPFM) measurements on carbon nanotubes and C60 adsorbed onto a hydrogen-terminated diamond(001) surface. A clear reduction in the Kelvin signal is observed at the position of the carbon nanotubes and C60 molecules as compared with the bare, air-exposed surface. This result can be explained by the high positive electron affinity of carbon nanotubes and C60, resulting…
The Interplay of Contact Layers: How the Electron Transport Layer Influences Interfacial Recombination and Hole Extraction in Perovskite Solar Cells.
2018
Charge-selective contact layers in perovskite solar cells influence the current density–voltage hysteresis, an effect related to ion migration in the perovskite. As such, fullerene-based electron transport layers (ETLs) suppress hysteresis by reducing the mobile ion concentration. However, the impact of different ETLs on the electronic properties of other constituent device layers remains unclear. In this Kelvin probe force microscopy study, we compared potential distributions of methylammonium lead iodide-based solar cells with two ETLs (planar TiO2 and C60-functionalized self-assembled monolayer) with different hysteretic behavior. We found significant changes in the potential distributio…
Synthesis of a Fullerene[60] Cryptate and Systematic Langmuir-Blodgett and Thin-Film Investigations of Amphiphilic Fullerene Derivatives
1995
The synthesis of the first fullerene cryptate 7 with a sodium ion bound to a benzo[2.2.2]cryptand covalently attached to a methanofullerene[60] is described. The amphiphilic properties of 7 as well as of a variety of other covalent fullerene derivatives with polar functional groups and the ability of these compounds to form Langmuir monolayers at the air-water interface were investigated in a systematic study. Among these derivatives are Diels-Alder adducts of C60 and methanofullerenes, four of which are fullerene C-glycosides. The films at the water surface were characterized by their surface pressure versus molecular area isotherms, compression and expansion cycles, and optical light micr…
Fullerenes(nC60) affect the growth and development of the sediment-dwelling invertebrate Chironomus riparius larvae
2015
Abstract The possible toxicity of nanoparticles (NPs) to aquatic organisms needs to be investigated for chronic effects at low concentrations. Chronic effects of carbon NPs, fullerenesC60, on the midges of Chironomus riparius at different life stages on larvae and adult midges were investigated. Sediment associated fullerenesC60 were studied by 10-day growth and 42-day emergence tests with artificial sediment at nominal concentration ranges 0.0004–80 mg/kg dry weight. The body length decreased in the lower tested concentrations (0.0025–20 mg/kg), but the effect vanished with higher concentrations. Delayed emergence rate observed at 0.5 mg/kg. The observed effects correlated with analyzed se…
Hybrid catalysts for CO 2 conversion into cyclic carbonates
2019
The conversion of carbon dioxide into valuable chemicals such as cyclic carbonates is an appealing topic for the scientific community due to the possibility of valorizing waste into an inexpensive, available, nontoxic, and renewable carbon feedstock. In this regard, last-generation heterogeneous catalysts are of great interest owing to their high catalytic activity, robustness, and easy recovery and recycling. In the present review, recent advances on CO 2 cycloaddition to epoxide mediated by hybrid catalysts through organometallic or organo-catalytic species supported onto silica-, nanocarbon-, and metal-organic framework (MOF)-based heterogeneous materials, are highlighted and discussed.
Synthesis, properties and charge transfer complexes of covalently attached [60]fullerene-tetrathiafulvalenes
1997
Abstract The synthesis of several fulleropyrrolidines bearing differently substitued tetrathiafulvalenes is reported. The synthetic approach used allows the introduction of ethylene spacers between the TTF and the C 60 core. Charge transfer complexes obtained from these [60]fullerene-TTF systems by reaction with tetrafluoro-tetracyano-p-quinodimethane (TCNQF 4 ) show a semiconducting behaviour; theoretical calculations predict an intramolecular CT band from the TTF moiety to the C 60 core.
Hexakis-adducts of [60]fullerene as molecular scaffolds of polynuclear spin-crossover molecules
2021
A family of hexakis-substituted [60]fullerene adducts endowed with the well-known tridentate 2,6-bis(pyrazol-1-yl)pyridine (bpp) ligand for spin-crossover (SCO) systems has been designed and synthesized. It has been experimentally and theoretically demonstrated that these molecular scaffolds are able to form polynuclear SCO complexes in solution. UV-vis and fluorescence spectroscopy studies have allowed monitoring of the formation of up to six Fe(ii)–bpp SCO complexes. In addition, DFT calculations have been performed to model the different complexation environments and simulate their electronic properties. The complexes retain SCO properties in the solid state exhibiting both thermal- and …